Chinese scientists have developed a new battery system that could enable lithium cells to operate safely for thousands of hours, an advance with potential implications for electric vehicles and power grids. The technology uses a novel electrolyte based on fluorinated amides, part of a class called deep eutectic gel electrolytes (DEGEs).
Lithium metal batteries are highly valued for their energy storage capacity but face safety and durability challenges. Conventional liquid electrolytes risk leakage and combustion, and during charging, lithium can grow into needle-like structures that compromise performance. DEGEs offer high charge conduction and thermal stability, addressing these issues.
In a study published in the Journal of the American Chemical Society, researchers from Nankai University developed a DEGE using the chemical 2,2,2-trifluoro-N-methylacetamide. This fluorinated compound helps suppress the formation of detrimental lithium dendrites while maintaining efficient ion transport.
Tests revealed that cells with the new electrolyte cycled stably for over 9,000 hours, with some designs retaining more than 80% of their capacity after 2,500 charging cycles. Even at elevated temperatures of about 80°C, one version maintained stability for 300 cycles.
“By introducing fluorinated groups into DEGEs, we achieved not only enhanced interfacial stability but also markedly improved cycling durability and thermal safety,” said Tianfei Liu, an author of the study. Co-author Kai Zhang added that the work “offers a blueprint for the next generation of high-performance electrolyte design.”
The findings suggest that fluorination and gel confinement can overcome long-standing limitations of lithium metal batteries, paving the way for their use in electric vehicles and grid-scale storage.
